There has conventionally been an image processing device for performing predetermined processing selected from various image processing functions thereof with respect to a document image inputted from a document image reading section, and outputting the processed image from a printer section. The image processing device has been strongly desired to process a large volume of documents efficiently in a short time. In order to meet such a strong desire, for example, a digital copying machine for automatically processing and outputting a large volume of documents has been developed.
In addition, a multi-functional digital copying machine has been commercialized and available on the market. The multi-functional digital copying machine can not only output from a printer section a document image inputted from a document reading section, but also output, by using a facsimile function and a printer function, an image inputted from an external device.
Such image processing devices are required to be built to meet basic specifications to achieve high-speed-operation, high-quality-image-production, multifunction, lowcost, low-energy-consumption. Furthermore, it is strongly desired that the image processing devices should rapidly and accurately perform the whole processing from reading of a document image to outputting of the inputted image, and recover from troubles such as a jam.
In some digital copying machines, a recirculating automatic document feeder is provided so as to meet the demand for improving the operation efficiency. If a jam occurs when reading a document in the recirculating automatic document feeder, smooth recovery from the jam is essential for achieving an efficient operation.
If recovery from a trouble cannot be carried out smoothly, the operation efficiency and reliability of the device are remarkably decreased. Thus, various devices for achieving smooth recovery from a trouble have been disclosed.
For example, Japanese Publication of Unexamined Patent Application No. 66586/1990 (Tokukaihei 2-66586) discloses an image processing device that smoothly recovers from a jam in the following manner. Specifically, if the image processing device detects that a document is placed on a platen with a different side facing up when starting copying, the document is automatically turned over. This arrangement saves the operator from inconvenience to reset documents one by one.
More specifically, according to the above-mentioned publication (Tokukaihei 2-66586), the image processing device is provided with a document side detecting section, a document recovery processing section, and a judging section for judging whether a discharge document has been copied or not. The document side detecting section detects which side (surface) of the document on the platen faces up. The document recovery processing section compares the detected document side with a document side to be copied next, and turns upside down the document if a different side faces up. If the image processing device detects that a document is placed on a platen with a different side facing up when starting copying, the document is automatically turned over. In addition, when the image processing device is caused to stop, it works out from which page the processing should be restarted, by judging from the number of copy sheets and the documents to which the processing is performed successfully, and determines whether a document purge is necessary or not. This arrangement saves the operator from inconvenience to reset documents one by one, and improves the operation efficiency in recovering from a jam.
However, as described above, since the image processing devices are desired to efficiently process the images inputted from external devices as well as a large volume of document images, it is necessary for the image processing devices to process the inputted images according to a more complicated method for control and management than conventional devices so as to recover from troubles in various modes.
Specifically, the above publication (Tokukaihei 2-66586) only mentions improvement of the operation efficiency achieved by comparing the number of copy sheets with the number of documents when recovering from a jam. However, it does not mention a method, for managing inputted images, which allows the image processing device to cope with troubles when it receives images from, for example, a facsimile machine or a personal computer. Thus, the above image processing device still takes time to recover from such troubles.
Another problem of the above-mentioned image processing device is as follows. When a transport error in the recirculating automatic document feeder occurs in processing a large volume of documents while reading the following document or when a trouble such as a jam occurs in successively outputting images inputted in a plurality of modes, if recovery from the jam is not accurately carried out in the process of reading the document images or the process of outputting the document images, it may be uncertain how far the image processing has processed, and time-wasting processes of re-reading and re-processing the images may be required. Therefore, the conventional method for managing the inputted image does not satisfactorily improve the operation efficiency of the image processing device.
Furthermore, a control section executing the method for the management becomes more complicated than a control section that does not execute such management. Thus, the image processing device requires a processor with higher-performance, an accompanying peripheral circuit, etc. so as to prevent the operation efficiency from decreasing, thereby raising the cost of the product.